ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 26, Number 5
JKCSEZ 26(5)
October 20, 1982 

The presence of 10 mole percent triphenyl borate accelerated dramatically the rate of reduction of structurally different sulfoxides with borane in tetrahydrofuran at room temperature, compared to the slow reduction with borane itself. Tetramethylene sulfoxide underwent complete reduction in 5 min and diethyl sulfoxide, dibenzyl sulfoxide and benzylphenyl sulfoxide were reduced quantitatively within 1h, whereas the reduction of diphenyl sulfoxide was rather slow, giving diphenyl sulfide in 90% yield in 24h. Boron trifluoride etherate and triethyl borate were less effective than triphenyl borate. A possible mechanism is presented.